Historical clue formulations

• Orchestral introduction in a musical or opera — 2022-08-22
• When an opera's musical themes may be established — 2020-01-09
• Intro — 2010-12-23
• Warm-up — 2004-03-20
• Chopin piece — 2003-12-04
• One of Chopin's 26 — 2003-04-12
• Musical intro — 1994-11-15
• Musical intro — 1994-10-06